Field of the Invention
The present disclosure relates to a fundus imaging apparatus that can capture a fundus image of a subject eye, a method for controlling the fundus imaging apparatus, and a storage medium storing a program for causing a computer to realize the control method.
Description of the Related Art
An aberration correction technique for correcting aberration of a subject eye is conventionally known and applied to a fundus imaging apparatus, according to which a wavefront sensor disposed at a position conjugate with a pupil of the subject eye detects the wavefront of reflected light when the light is projected and reflected on a fundus of the subject eye and a correction device is controlled in such a way as to correct aberration of the detected wavefront of the reflected light. The above-mentioned aberration correction technique is applicable to the imaging of a micro portion on the fundus of the subject eye with high resolution. For example, the captured micro portion image can be used to diagnose information about the shape and density of a photoreceptor cell and the flow of blood corpuscles for the purpose of research.
For example, an ophthalmology apparatus discussed in Japanese Patent Application Laid-Open No. 2015-104468 includes a scanning unit configured to perform scanning by projecting measurement light on the fundus of a subject eye, an adjustment unit configured to perform focus adjustment for the measurement light projected on the fundus at a plurality of imaging planes in an optical axis direction, a correction unit configured to correct the aberration occurring in the subject eye, and an image capturing unit configured to capture images of the plurality of imaging planes. The ophthalmology apparatus calculates a focus shift amount between a focus position for acquiring an image of a first imaging plane and a focus position for acquiring an image of a second imaging plane, spaced from the first imaging plane by a predetermined distance in the optical axis direction, according to diopter of the subject eye. The adjustment unit performs the focus adjustment according to the calculation result. The above-mentioned configuration discussed in Japanese Patent Application Laid-Open No. 2015-104468 is useful to capture an image of the fundus of the subject eye with high image quality.
Further, a technique capable of measuring the blood flow of a blood vessel is, for example, discussed in Japanese Patent Application Laid-Open No. 2012-176093. The discussed technique includes identifying a blood vessel region of an imaging target, identifying information relating to the blood flow velocity of the blood vessel based on a Scanning LASER Ophthalmoscope (SLO) image generated by a signal light obtained at a focus position deeper than the blood vessel region, and acquiring information relating to the blood flow of the blood vessel based on the identified region and the information relating to the blood flow velocity.
However, when a fundus of a subject eye is imaged according to the above-mentioned conventional technique, if the thickness of an optical diffusive layer of the fundus is greater at a peripheral portion compared to a central portion, a problem that the image quality of the peripheral portion deteriorates greatly compared to the central portion may occur. In this respect, the inventor believes that a physical structure of the optical diffusive layer of the fundus of the subject eye and a related optical function possibly induce the problem that the image quality deteriorates greatly at the peripheral portion of the fundus.